In this study, scattering of plane electromagnetic waves at the junction formed by a PEC half-plane and a halfplane with anisotropic conductivity is investigated. By using a Fourier transform technique, the problem is formulated into a matrix Wiener-Hopf system, and a rigorous solution is obtained. Also, to show the effect of planar physical discontinuity explicitly, four different special cases are considered where the problems are reduced into pairs of simultaneous Wiener Hopf equations. They are decoupled via polynomial transformations and solved through the standard procedure. The diffracted fields are expressed in a form suitable for GTD applications.